Soda, you know my favourite is 'let's kill all the lawyers' from Get Over It which originates from Henry VI Part 2: All:
God save your majesty!
Cade:
I thank you, good people—there shall be no money; all shall eat
and drink on my score, and I will apparel them all in one livery,
that they may agree like brothers, and worship me their lord.
Dick:
The first thing we do, let's kill all the lawyers.
Cade:
Nay, that I mean to do.
Henry The Sixth, Part 2 Act 4, scene 2, 71–78
While I am not a great fan of the line 'someone show me how to tell the dancer from the dance' in Saturday Night, I am a fan of the man who wrote the original, W.B. Yeats:
Labour is blossoming or dancing where
The body is not bruised to pleasure soul.
Nor beauty born out of its own despair,
Nor blear-eyed wisdom out of midnight oil.
O chestnut-tree, great-rooted blossomer,
Are you the leaf, the blossom or the bole?
O body swayed to music, O brightening glance,
How can we know the dancer from the dance?
Stanza 8 of Among School Children (The Tower, 1928 )
I don't know if the title of Glenn's song Brave New World is taken from Shakespeare's The Tempest or Aldous Huxley's book. It's a common phrase.
MIRANDA Oh, wonder!
How many goodly creatures are there here!
How beauteous mankind is! O brave new world,
That has such people in ’t!
Act 5 Scene 1
I should also say that in 1977 I found it astounding that a pop song would use the phrase 'great expectations' (Charles Dickens) & that was one aspect which eventually led to the song becoming my favourite Eagles song.